Small Animal Imaging Core The main goal of this small animal imaging (SAI) core is to support the proposed projects 1 - 4. Specifically, we will establish/develop the required imaging systems and methods so as to critically evaluate the nanoparticles developed in projects 1, 2 and 4 regarding their bio-distribution, half-life, effectiveness of providing imaging contrast, and potential ability to depict molecular events. In addition, imaging methods and image analysis tools focusing on monitoring lesion progression will also be developed. Furthermore, a direct comparison of the image quality between the proposed SAI computed tomography (CT) system in project 3 and a commercially available SAI CT will be conducted in order to provide strategies for the design of the proposed CT system. Currently, the small animal imaging facility at UNC houses a 3T magnetic resonance imaging (MRI) scanner, single photon emission computed tomography (SPECT) system, and in vivo optical imaging system. While these imaging systems are capable of providing high quality small animal images, additional developments specifically to serve the needs of the proposed projects 1 - 4 are needed. To this end, we will purchase and establish a high field SAI MR scanner to provide much higher spatial resolution images and improved sensitivity to iron oxide based contrast agents (proposed in projects 1, 2, and 4) in Aim 1a. A commercially available CT system will be purchased in Aim 1b to provide high quality and stable CT images for longitudinal studies. Aim 1c will further establish a web site that manages machine times and accesses to a dedicated PACS system. In contrast, Aim 2 will focus on developing/evaluating the nanoparticles developed in projects 1, 2, and 4 by utilizing MR, SPECT, and Ol (Aim 2a), direct comparing results from project 3 and that obtained from a commercially available CT system (Aim 2b), and developing multi-modality image analysis tools (Aim 2c).